CVE-2026-44327 | THREATINT

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-oam route group without inbound OAuth2/bearer-token authorization. A network attacker who can reach NEF on the SBI can hit the OAM route with no Authorization header at all and the handler returns 200 OK. The current OAM handler is a stub that returns null, but the structural defect is route-group-scoped: the entire OAM route group has no inbound auth middleware, so every future OAM operation added to this group inherits the missing auth boundary by default. This vulnerability is fixed in 4.2.2.

PUBLISHED Reserved 2026-05-05 | Published 2026-05-27 | Updated 2026-05-28 | Assigner GitHub_M

CRITICAL: 10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H

Problem types

CWE-306: Missing Authentication for Critical Function

CWE-862: Missing Authorization

Product status

< 4.2.2

affected

References

github.com/...ree5gc/security/advisories/GHSA-cmpj-2x3g-m7g3 exploit

github.com/...ree5gc/security/advisories/GHSA-cmpj-2x3g-m7g3

github.com/free5gc/free5gc/issues/861

github.com/free5gc/nef/pull/23

cve.org (CVE-2026-44327)

nvd.nist.gov (CVE-2026-44327)

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